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United States Patent |
5,029,007
|
Spiero
|
July 2, 1991
|
Combination of a video tuner, a video signal reproducing arrangement and
a picture display unit
Abstract
A video tuner (1), a video signal (recording and) reproducing arrangement
(7) and a picture display unit (35) are coupled to each other via a
switching circuit (9). The video tuner (1) can supply first and second
video signals on its output (3), representing pictures having a first and
a second aspect ratio respectively (4:3 and 16:9, respectively). These
signals can be recorded and reproduced by the video signal (recording and)
reproducing arrangement (7) and can be displayed with the correct aspect
ratio by the picture display unit (35). In order to realize this, a
control signal line (55) is arranged between a control signal output (4)
of the tuner (1), a control signal input and output terminal (10) of the
video signal (recording and) reproducing arrangement (7) and control
signal inputs (36) of the picture display unit and (46) of the switching
circuit and control signal detector (9, 45). The video tuner (1) produces
a first or a second control signal (S1 and S2) on the output (4) depending
on the aspect ratio of the pictures in the supplied video signal while the
video signal (recording and) reproducing arrangement (7) produces a third
or a fourth control signal on the control signal input and output terminal
(10) depending on the aspect ratio of the pictures in the video signal
being reproduced. The switching circuit and detector (9, 45) select
between the control signals in such a way that if the first or the second
control signal is applied, the output signal of the video tuner (1) is
selected, and if the third or the fourth control signal is applied, the
output signal of the video signal (recording and) reproducing arrangement
(7) is transferred to the picture display unit (35). The picture display
unit (35) selects between the control signals in such a way that video
signals applied to the input (37) are displayed with the correct aspect
ratio on the display screen (39).
Inventors:
|
Spiero; Richard C. (Eindhoven, NL)
|
Assignee:
|
U.S. Philips Corporation (New York, NY)
|
Appl. No.:
|
521289 |
Filed:
|
May 7, 1990 |
Foreign Application Priority Data
Current U.S. Class: |
348/556; 348/558; 348/706 |
Intern'l Class: |
H04N 005/268; H04N 011/20; H04N 007/01; H04N 005/50 |
Field of Search: |
358/181,191.1,141,12,140,11,142
360/9.1,61,62
334/47,86
|
References Cited
U.S. Patent Documents
4303940 | Dec., 1981 | Ciciora | 358/140.
|
4303944 | Dec., 1981 | Kitamura | 358/191.
|
4488180 | Dec., 1984 | Rabinowitz | 358/181.
|
4574279 | Mar., 1986 | Roberts | 358/140.
|
4729012 | Mar., 1988 | Jose et al. | 358/140.
|
4736457 | Apr., 1988 | Kupfer | 334/47.
|
4831446 | May., 1989 | Nakajima et al. | 358/181.
|
4864421 | Sep., 1989 | Morioka et al. | 358/181.
|
4873583 | Oct., 1989 | Kobayashi et al. | 360/61.
|
4901148 | Feb., 1990 | Nakayama et al. | 358/140.
|
4931855 | Jun., 1990 | Salvadorini | 358/142.
|
4963991 | Oct., 1990 | Honjo | 360/9.
|
Primary Examiner: Groody; James J.
Assistant Examiner: Murrell; Jeffrey S.
Attorney, Agent or Firm: Goodman; Edward W.
Claims
I claim:
1. A combination of a video tuner, a video signal reproducing arrangement
and a picture display unit, the video reproducing arrangement and a
picture display unit, the video tuner having a first tuner output for
supplying a tuner video signal, the reproducing arrangement being
constructed to read a reproduced video signal from a record carrier and to
supply the reproduced video signal thus read to a first output, and the
picture display unit having a first input for receiving an applied video
signal, the combination further comprising switching means having a first
signal input coupled to the first tuner output of the video tuner, a
second signal input coupled to the first output of the reproducing
arrangement, a signal output coupled to the first input of the picture
display unit, and a control signal input, the switching means being
constructed to selectively establish a coupling between one of the first
and second signal inputs and the signal output depending on a control
signal applied to the control signal input, characterized in that the
video tuner is adapted to alternatively supply to the first tuner output,
a first tuner video signal representing pictures having a first aspect
ratio, and a second tuner video signal representing pictures having a
second aspect ratio, the video tuner further comprising a second tuner
output and means for supplying at said second tuner output a first control
signal when the video signal at said first tuner output is said first
tuner video signal, and a second control signal when the video signal at
said first tuner output is said second tuner video signal; said
reproducing arrangement being adapted to read a first reproduced video
signal representing pictures having said first aspect ratio, and a second
reproduced video signal representing pictures having said second aspect
ratio, said reproducing arrangement further comprising a second output and
means for supplying to said second output a third control signal when the
video signal read by said reproducing arrangement is said first reproduced
video signal, and a fourth control signal when the video signal read by
said reproducing arrangement is said second reproduced video signal,
wherein said means for supplying said third and fourth control signals
receives a first and a second auxiliary signal, respectively, read from
the record carrier denoting the aspect ratios of said first and second
reproduced video signals, respectively; and the second tuner output and
the second output of the reproducing arrangement being both coupled to the
control signal input of the switching means and to a second input of the
picture display unit, wherein the switching means couples the first signal
input to the signal output upon receipt of either one of said first and
second control signals, and couples the second signal input to the signal
output upon receipt of either one of said third and fourth control
signals, and wherein the picture display unit displays said first tuner
video signal with said first aspect ratio upon receipt of said first
control signal, said second tuner video signal with said second aspect
ratio upon receipt of said second control signal, said first reproduced
video signal with said first aspect ratio upon receipt of said third
control signal, and said second reproduced video signal with said second
aspect ratio upon receipt of said fourth control signal.
2. A combination as claimed in claim 1, wherein the video signal
reproducing arrangement is a video signal recording and reproducing
arrangement having a first input coupled to the first tuner output of said
video tuner for receiving the tuner video signal, characterized in that
said video signal recording and reproducing arrangement further comprises
a second input coupled to the second tuner output and is adapted to record
the first tuner video signal upon receipt of said first control signal,
and the second tuner video signal upon receipt of said second control
signal, said video signal recording and reproducing arrangement further
comprising means for recording the first auxiliary signal upon receipt of
said first control signal and for recording the second auxiliary signal
upon receipt of said second control signal, wherein said second input and
said second output of said video signal recording and reproducing
arrangement are combined to form a single input-output terminal.
3. A combination as claimed in claim 1 or 2, characterized in that the
switching means further comprise a detector unit having an input coupled
to the second tuner output of the video tuner and to the second output of
the reproducing arrangement and having an output coupled to the
control-signal input of the switching means, the switching means and the
detector unit being constructed in such a way that, when either one of the
first and the second control signals is applied to the input of the
detector unit, said detector unit supplies a control signal to the control
signal input of the switching means causing the switching means to
establish a coupling between the first signal input and the signal output,
and when either one of the third and the fourth control signals is applied
to the input of the detector unit, said detector unit supplies a further
control signal to the control signal input of the switching means causing
the switching means to establish a coupling between the second signal
input and the signal output.
4. A combination as claimed in claim 1 or 2 characterized in that the
picture display unit further comprises a detector unit having an input
coupled to the second turner output and to the second output of the
reproducing arrangement, and having an output coupled to the second input
of the picture display unit, wherein the detector unit is responsive to
either one of the first and the third control signals applied to its input
to supply a control signal to the second input of the picture display unit
causing the picture display unit to be adapted to display the applied
video signal with the first aspect ratio on the display screen, and the
detector unit is responsive to either one of the second and the fourth
control signals applied to its input to supply a further control signal to
the second input of the picture display unit causing the picture display
unit to be adapted to display the applied video signal with the second
aspect ratio on the display screen.
5. A combination as claimed in claim 1, characterized in that the first,
the second, the third and the fourth control signals are direct voltage
signals whose d.c. values are situated in a first, a second, a third and a
fourth direct voltage range, respectively, wherein said first, second,
third and fourth direct voltage ranges do not overlap one another.
6. A television set comprising the video tuner, the picture display unit
and the switching means of the combination as claimed in display unit and
the switching means of the combination as claimed in claim 1,
characterized in that the television set comprises a first and a second
input terminal and a first and a second output terminal, the first tuner
output of the video tuner being coupled to the first output terminal, the
first input terminal being coupled to the second input of the switching
means, the second tuner output of the video tuner being coupled to the
second output terminal, and the second input terminal being coupled to the
second input of the picture display unit, and wherein the second output
terminal and the second input terminal are combined to form a single
input-output terminal.
7. A recording and reproducing arrangement for use in a combination as
claimed in claim 2, characterized in that the input-output terminal is
coupled to an input of a detector unit, and in that during recording, the
detector unit is responsive to one of the first and the third control
signals received on its output to record the first auxiliary signal on the
record carrier, and is responsive to one of the second and the fourth
control signals received on its input to record the second auxiliary
signal on the record carrier.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a combination of a video tuner, a video signal
reproducing arrangement and a picture display unit, the video tuner having
a first output for supplying a video signal, the reproducing arrangement
being constructed to read a video signal from a record carrier and to
supply the video signal thus read to a first output, and the picture
display unit having a first input for receiving a video signal, the
combination further comprising switching means having a first signal input
coupled to the first output of the video tuner, a second signal input
coupled to the first output of the reproducing arrangement, having a
signal output coupled to the first input of the picture display unit, and
a control signal input, the switching means being constructed to establish
a coupling between the first signal input and the signal output or between
the second signal input and the signal output depending on a control
signal applied to the control signal input. The invention also relates to
a combination as defined above, in which the video signal reproducing
arrangement is a video signal recording and reproducing arrangement,
having a first input for receiving a video signal, which input is coupled
to the first output of the video tuner.
The invention further relates to a video signal (recording and) reproducing
arrangement and to a picture display unit for use in the combination, and
to a television set comprising a video tuner, the picture display unit and
the switching means of the combination.
2. Description of the Related Art
The combination comprising the video tuner, the video signal recording and
reproducing arrangement and the picture display unit is known from
Funk-Technik 38 (1983), Heft 5, pp. 208-212. This publication, in
particular FIG. 1, shows a combination in which the video tuner, the
switching means and the picture display unit have been combined to form a
television set and in which the video signal recording and reproducing
arrangement supplies a control signal for the switching means if a video
signal reproduced by the arrangement is to be displayed on the screen of
the picture display unit.
Also known are video tuners which are constructed to supply a first video
signal representing pictures having a first aspect ratio or a second video
signal representing pictures having a second aspect ratio. This first
aspect ratio is for example 4:3, being the width-height ratio of the
television pictures in existing television programs to be displayed on a
standard display screen. The second aspect ratio is for example 16:9,
being a width-height ratio which is more in conformity with movie
technology and which is better adapted to motionpicture film and to the
properties of the human eye.
An example of such a video tuner is the MAC decoder as described in Philips
Technisch Tijdschrift 43, no. 8, Dec. 1986, pp. 213-229. The MAC decoder
is employed for receiving satellite programs, the decoder deriving first
or second video signals to be subsequently displayed with the correct
aspect ratio on the display screen of the picture display unit.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a combination of a video tuner,
a video signal reproducing arrangement and a picture display unit,
enabling first and second video signals to be reproduced with the correct
aspect ratio on the picture display unit (display screen) either by means
of the video tuner or by means of the reproducing arrangement, the picture
display unit being capable of correctly selecting between the two signal
sources.
It is another object of the invention to provide a combination of a video
tuner, a video signal recording and reproducing arrangement and a picture
display unit, enabling first and second video signals generated by the
video tuner to be displayed directly on the picture display unit with the
correct aspect ratio, enabling said video signals to be recorded on the
recording and reproducing arrangement, enabling them to be subsequently
displayed with the correct aspect ratio on the display unit, the picture
display unit also being capable of correctly selecting between the two
signal sources. For this purpose the combination in accordance with the
invention, comprising the video signal reproducing arrangement, is
characterized in that the video tuner is adapted to supply a first video
signal representing pictures having a first aspect ratio, or a second
video signal representing pictures having a second aspect ratio, to the
first output, in that the video tuner further comprises a second output
for supplying a first or a second control signal depending on whether the
video signal to be supplied by the video tuner is a first or a second
video signal, in that the reproducing arrangement is adapted to read a
first or the second video signal from the record carrier and to supply the
video signal thus read to the first output, in that the reproducing
arrangement further comprises a second output for supplying a third or a
fourth control signal depending on whether the video signal to be supplied
by the arrangement is the first or the second video signal, in that the
reproducing arrangement is further adapted to read from the record carrier
a first or a second auxiliary signal which is characteristic of the first
or the second video signal recorded on the record carrier and, under the
influence of the auxiliary signal thus read, to derive the third or the
fourth control signal and to supply the control signal to the second
output, in that the second output of the video tuner and the second output
of the reproducing arrangement are coupled both to the control signal
input of the switching means and to a second input of the picture display
unit, in that the switching means are adapted to establish a coupling
between the first signal input and the signal output when the first or the
second control signal is applied to the control signal input, and to
establish a coupling between the second signal input and the signal output
when the third or the fourth control signal is applied to the control
signal input, and in that the picture display unit is adapted to display
the first video signal applied to its first input with the first aspect
ratio on a display screen upon reception of the first or the third control
signal applied to its second input and is adapted to display the second
video signal applied to its first input with the second aspect ratio upon
reception of the second or the fourth control signal applied to its second
input. For said purpose, the combination in accordance with the invention,
comprising the video signal recording and reproducing arrangement is
further characterized in that the recording and reproducing arrangement is
adapted to record the first or the second video signal applied to its
first input on the record carrier and has a second input for receiving the
first or the second control signal, which second input is coupled to the
second output of the video tuner, in that the recording and reproducing
arrangement is further adapted to record the first or the second auxiliary
signal on the record carrier depending on the first or the second control
signal applied to the second input, and in that the second output and the
second input of the recording and reproducing arrangement are combined to
form a single input-output terminal. In order to ensure that the first or
the second video signals supplied by the decoder are displayed correctly
by the picture display unit, the video signals supplied to the picture
display unit by the decoder should be accompanied with an indication
whether the signals applied to the first input of the picture display unit
are first or second video signals. Similarly, the video signal reproducing
arrangement can supply first and second video signals to the picture
display unit. Again the video signals applied to the picture display unit
should be provided with an indication to specify the type of the video
signals, enabling the video signals supplied by the reproducing
arrangement to be displayed with the correct aspect ratio on the display
screen. Moreover, the picture display unit should be capable of detecting
which source, the video tuner or the reproducing arrangement, supplies
video signals with their associated identifications to the picture display
unit, to enable it to be changed over to the correct source with the aid
of the switching means. In particular, since the second input and the
second output of the recording and reproducing arrangement have been
combined in this arrangement, steps are needed to ensure that the picture
display unit and the switching means correctly receive the information
indicating the aspect ratio of the video signal suppled to the picture
display unit by the video tuner and the recording and reproducing
arrangement and the information indicating the source supplying the video
signal. The invention is based on the recognition of the fact that it is
possible to provide all this information via a single electrical line. By
means of this single electrical line, a coupling is established between
the video tuner, on the one hand, and the switching means and the picture
display unit, on the other hand, and between the video tuner and the
(recording and) reproducing arrangement as well as between the
(recording/)reproducing arrangement, on the one hand, and the switching
means and the picture display unit, on the other hand, via which coupling
the information transfer of the control signal can be realized. For the
picture display unit, it is then important that it is capable of selecting
between the first and the third control signal, on the one hand, and the
second and the fourth control signal, on the other hand, so that the
picture display unit can detect the aspect ratio of the pictures in the
video signal applied to its first input. For the switching means, it is
important that it is capable of selecting between the first and the second
control signal, on the one hand, and the third and the fourth control
signal, on the other hand, so that the switching means can identify the
source supplying the video signals.
Particularly in the case that the video tuner, the picture display unit and
the switching means are combined in a television set, the electrical
connection between this television set and the recording and reproducing
arrangement, for example a video recorder, can be realized by means of a
SCART cable, which is known per se. To transfer the four control signals,
use can be made of line 8 in the SCART cable. For a publication on the
SCART cable, reference is made to the afore-mentioned article in
Funk-Technik. The first, the second, the third and the fourth control
signal are then preferably direct voltage signals having d.c. values
within a first, a second, a third and a fourth voltage range, which four
voltage ranges do not overlap each other.
For the first and the third voltage ranges the voltage ranges of 0-2 V and
9.5-12 V already defined in the present SCART standard may be used, see
Table 1 in the Funk-Technik article. In accordance with the present SCART
standard, a control signal in the voltage range from 0-2 V indicates that
a normal television signal is applied to the picture display unit via the
video tuner. In accordance with the current SCART standard, a control
signal in the voltage range from 9.5-12 V indicates that an external
source, such as a video recorder, supplies a video signal to the picture
display unit.
The change over point for the switching means is situated at approximately
5.5 V. Consequently, when the recording and reproducing arrangement (video
recorder) supplies a control signal of a value larger than 5.5 V to the
control signal input of the switching means, the switching means connect
the first output of the recording and reproducing arrangement to the first
input of the picture display unit. When a control signal of a value
smaller than 5.5 V is applied to the control signal input of the switching
means, the switching means change over to connect the first output of the
video tuner to the first input of the picture display unit. If now two
intermediate voltage ranges are added to the existing standard, the second
voltage range being selected between for example 4 and 5 V and the fourth
voltage range between for example 6 and 7 V, this enables a parameter
which is characteristic of the aspect ratio of the pictures in the video
signal to be transmitted with the source selection control signal. In this
respect, it is to be noted that the recording and reproducing arrangement
has converted the first or second control signal associated with a video
signal and applied to the arrangement during recording into a third or a
fourth control signal during subsequent reproduction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail, by way of example; with
reference to the Figures. In the Figures:
FIG. 1 shows and example of the four control signals;
FIG. 2 shows a first embodiment of the combinations; and
FIG. 3 shows a second embodiment of the combination.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The combination shown in FIG. 2 comprises a video tuner 1, for example
equipped with a D2 MAC decoder 2. The tuner 1 has a first output 3 and a
second output 4. The first or second video signals are supplied via the
output 3. The first video signals are made up of pictures having an aspect
ratio of 4:3. The second video signals are made up of pictures having an
aspect ratio of 16:9. The D2 MAC decoder receives D2 MAC signals and
converts these video signal into CVBS (chroma-video-blanking-sync)
signals. The aspect-ratio information is contained in the D2 MAC signals
themselves. The tuner 1 extracts this information from the D2 MAC signal
and, depending on whether the aspect ratio of the pictures in the video
signals is 4:3 or 16:9, the tuner 1 supplies a first control signal S1 or
a second control signal S2 to its output 4. In the present example the
first control signal S1 is a direct voltage signal having a d.c. amplitude
in the voltage range from 0 V to 2 V, see FIG. 1. In the present example
S1 is 0 V. The second control signal S2 is also a direct voltage signal
having a d.c. amplitude in the voltage range from 4 V to 5 V, see FIG. 1.
In the present example S2 is 4.5 V. For this purpose, the tuner 1
comprises a switch 5 which is controlled by a switching signal generated
by the D2 MAC decoder 2, which switching signal in fact indicates whether
the pictures in the video signal supplied by the decoder 2 have an aspect
ratio of 4:3 or 16:9. In the first mentioned case, the decoder 2 supplies
such a switching signal to the switch 5, that this switch is in the
position shown. The direct voltage on the output 4 is then 0 V. In the
other case, the decoder 2 supplies such a control signal that the switch 5
occupies the other position. The input 4 is then coupled to a direct
voltage point at 4.5 V via the resistor R1 of, for example 1, kohm. Now a
direct voltage of 4.5 V appears on the output 4. The output 3 of the tuner
1 is coupled to a first input 6 of a recording and reproducing arrangement
7 and to a first input 8 of switching means 9. The output 4 of the tuner 1
is coupled to a second input 10 of the arrangement 7. The input 6 is
coupled to an input 11 of a read-write unit 12, in which the video signals
are processed in such a way that they can be recorded on the record
carrier 13.
Since in the present case the record carrier 13 takes the form of a
magnetic tape, the video signal processed by the unit 12 is applied to a
read-write head 15 via the output 14 to record the video information on
the record carrier 13. Recording can be effected in adjacent tracks which
are inclined relative to the longitudinal direction of the record carrier
13. Such an arrangement is referred to as a helical-scan video recorder.
The read-write unit 12 can also read the video information by means of the
read-write head 15, the information thus read being supplied to an output
16. During reproduction, the switch 17 is set to the position not shown
under the influence of a switching signal plb. As a result of this, the
output 16 is coupled to a first output 18 of the arrangement 7 via the
switch 17. The output 18 is coupled to a second input 19 of the switching
means 9.
The input 10 is coupled to an input 26 of a read-write unit 27 via a
detector 25. The output 28 of this unit 27 is coupled to a read-write head
29 or to the read-write head 15.
If a video signal generated by the tuner 1 is recorded on the record
carrier, the first or the second control signal is also applied to the
arrangement 7 via the input 10. For this purpose, an auxiliary signal
which is characteristic of the aspect ratio should also be recorded on the
record carrier 13. The detector 25 can now discriminate between the first
and the second control signal applied to the terminal 10. For this
purpose, the detector 25 comprises a comparator (not shown) having a
threshold value V3, see FIG. 1, which threshold value is 3 V in the
present example. Depending on which control signal (the first or the
second) is applied to the terminal 10, a first or a second auxiliary
signal is recorded on the record carrier, together with the associated
video signal, by means of the read-write unit 27 and, as the case may be,
the read-write head 29. This auxiliary signal may be recorded in a servo
track already present on the record carrier, which servo track is situated
at the edge of the record carrier and extends in the longitudinal
direction of the record carrier. During reproduction, the first or the
second auxiliary signal is read and by means of the unit 27 it is applied
to the switch 31 as a switching signal via the line 30. If the first
auxiliary signal is read, the switch 31 is in the position shown. If the
second auxiliary signal is read, the switch 31 is in the other position.
Since during reproduction the switch 32 is set to the position not shown
under the influence of the switching signal plb, a third control signal S3
is applied to the terminal 10 in the first mentioned case (the first
auxiliary signal is read). The third control signal S3 is for example a
direct voltage signal having a d.c. amplitude in a voltage range between
9.5 V and 12 V, see FIG. 1. FIG. 2 shows that S3 is 12 V. In the other
case, a fourth control signal S4 is applied to the terminal 10. The
control signal S4 is also a direct voltage signal and lies in a voltage
range between 6 V and 7 V.
FIG. 2 shows that the detector 25 also comprises a second comparator (not
shown) having a threshold value V1 of 8 V. This comparator is essential in
the case that the signal is copied from one video recorder to another
video recorder and the correct information about the aspect ratios should
also be copied.
FIG. 2 shows that S4 is 6.5 V. The resistance value of R2 may be, for
example, 330 .OMEGA.. Preferably, the resistance value of the R3 is
selected to be larger than 8 k.OMEGA.. The arrangement 7 may further
comprise an internal tuner 60 which is adapted to receive normal video
signals with pictures having an aspect ratio of 4:3. For this purpose the
switch 17 is always connected to the tuner 60, unless the arrangement is
set to reproduction. In that case the output 16 is coupled to the terminal
18.
The combination further comprises a picture display unit 35 having a first
input 36 and a second input 37. The second output 4 of the tuner 1 and the
terminal 10 of the arrangement 7 are both coupled to the input 37 of the
unit 35. An output 38 of the switching means 9 is coupled to the input 36
of the unit 35. Video signals representing pictures having an aspect ratio
of 4:3 or 16:9 applied to the input 36, are displayed on the display tube
39 of the unit 35.
In order to enable the pictures in the video signals to be reproduced with
the correct aspect ratio, the unit 35 further comprises a detector 40. The
detector 40 comprises two comparators (not shown) having threshold values
V3=3 V and V1=8 V. If a control signal applied to the detector 40 is
situated in the voltage range between 3 and 8 V the signal will be a video
signal representing pictures having an aspect ratio of 16:9 and applied to
the input 36. If the control signal applied to the detector 40 is situated
outside the range from 3 to 8 V the video signal applied to the input 36
represents pictures having an aspect ratio of 4:3. The detector 40
generates auxiliary signals characteristic of each case to drive the
display screen in such a way that in each case the pictures in the video
signal can be displayed on the screen 39 with the correct aspect ratio.
This means that if the television set has a display screen having an
aspect ratio of 4:3, pictures in a video signal having an aspect ratio of
4:3 will exactly fill the screen. Pictures in a video signal having an
aspect ratio of 16:9 will be reproduced with a picture with equal to the
width of the display screen but with a height which is smaller than the
height of the display screen. This means that a black horizontal band will
be formed at the top and the bottom of the picture. In the case of a
picture screen having an aspect ratio of 16:9, pictures in a video signal
having an aspect ratio of 16:9 will exactly fill the screen. Pictures in a
video signal having an aspect ratio of 4:3 will have a picture height
equal to the height of the picture screen. The width is smaller than the
width of the screen. Consequently, a black vertical band will be formed at
both sides of the picture.
The combination further comprises a detector 45 having an input 46, coupled
to the input 4, and having an output 47. The detector 45 comprises a
comparator (not shown) having a threshold value V2 of 5.5 V. If a control
signal having a voltage value smaller than 5.5 V is applied to the input
41 the detector 45 will supply such a switching signal to the switching
means 9 via its output 47 that said switching means are set to the
position shown. If a control signal having a voltage value larger than 5.5
V is applied to the input 46, the detector 45 will supply a switching
signal to set the switching means 9 to the other position not shown.
The combination operates as follows. The D2 MAC decoder 2 generates a video
signal having pictures with an aspect ratio of 4:3 or 16:9. This video
signal should be displayed by means of the picture display unit 35. The
tuner 1 supplies the video signal to the terminal 8 of the switching means
9 via the output 3. Moreover, a first control signal (S1=0 V because the
switch 5 and the switch 32 are in the position shown and because of the
coupling to ground via the resistor R4, whose resistance value is 4
k.OMEGA. or higher) or a second control signal (S2=4.5 V, because the
switch 5 is in under the position not shown) is generated on the output 4.
The first or the second control signal is applied to the detector 45 of
the switching means 9 and to the detector 40 of the picture display unit
35. The control signals S1 and S2 both ensure that the switching means 9
are set to the position shown, so that the video signal is applied to the
input 36 of the picture display unit 35. Depending on whether the control
signal applied to the detector 40 is a first (S1) or a second (S2) control
signal, the picture display unit 36 will display the pictures in the
applied video signal on the display screen 39 with an aspect ratio of 4:3
of 16:9.
Now the video signal generated by the D2 MAC decoder 2 should be recorded
on the record carrier 13 in the recording and reproducing arrangement 7.
The video signal is normally applied to the input 11 of the read-write
unit 12 via the terminals 3 and 6 and is recorded on the record carrier 13
by means of the head 15. The first or the second control signal is applied
to the detector 25 via the terminal 10. Depending on the aspect ratio (4:3
or 16:9), the read-write unit 27 and the head 29 record a first or a
second auxiliary signal on the record carrier.
Subsequently, the video signal is reproduced by the arrangement 7 and is
applied to the picture display unit 35 to display the video signal on the
screen 39. The video signal reproduced by the arrangement 7 is applied to
the input 19 of the switching means 9 via the output 18. The first or the
second auxiliary signal read from the record carrier causes the switch 31
to be set to the position shown or the position not shown, respectively.
If the video signal applied to the output 18 is a video signal having
pictures with an aspect ratio of 4:3, a third control signal S3 (=12 V) is
produced on the terminal 10. In the case of an aspect ratio of 16:9, a
fourth control signal S4 (=6.5 V) is generated on the terminal 10. This
control signal, which is applied to the detector 45, causes the switching
means 9 to change over to the other position, so that the video signals
are applied from the arrangement 7 to the input 36 of the picture display
unit 35. Since the detector 40 can discriminate between the third and the
fourth control signal, the pictures in the video signal applied to the
picture display unit 35 are displayed with the correct aspect ratio on the
screen 39.
The tuner 2, the picture display unit 35, the detector 45 and the switching
means 9 may form part of a television set 53. In that case the set
comprises three terminals 50, 51, 52 which are coupled to the output 3 of
the tuner 1, the terminal 19 of the switching means 9 and the output 4 of
the tuner 1, respectively. The connection between the television set 53
and the arrangement (video recorder) 7 can then be established by means of
a SCART cable (also referred to as EURO cable) 54. The terminals 10 and 52
of the arrangement 7 and the set 53 are then coupled to the pins 8 of the
SCART (EURO) connectors at both ends of this cable and to each other via
the line 55 in this SCART (EURO) cable.
FIG. 3 shows another combination. The combination bears much resemblance to
that shown in FIG. 2. The tuner 1, the switching means 9 and the picture
display unit 35 in the combination shown in FIG. 3 are the same as those
shown in FIG. 2. Instead of a recording and reproducing arrangement the
combination shown in FIG. 3 comprises a reproducing arrangement 7'. The
reproducing arrangement 7' is constructed as a magnetic-tape playback
arrangement. However, this is not necessary. Alternatively, the
reproducing arrangement 7' may be, for example, a CD video (CDV) player, a
CD interactive (CDI) player, or a Laservision player. A characteristic
feature is that such players have an output 10 for supplying the third or
the fourth control signal, depending on whether a first or a second video
signal appears on the output 18.
It is to be noted that the invention is not limited to the embodiments
disclosed herein. For example, the invention also applies to those
embodiments which differ from the embodiments shown in respects which are
not relevant to the invention. For example, the four control signals
transferred via the control signal line 55 may be of a different type.
Such control signals may be, for example, frequency-multiplexed. Moreover,
it is not necessary to employ an HD MAC decoder in the tuner 1. Another
possibility may be, for example, a decoder for MUSE signals.
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